Car refrigeration



Dec. 10, 1935. D. P. MINARD CAR REFRIGERATION Fild Nov. 9, 1954 L H E iii 6 2H 1 -bwriL 1-1L J 9 m J Patented Dec. 10, 1935 PATENT OFFICE CAR REFRIGERATION David I. Minard, Chicago, 111., assignor to Armomand Company, Chicago, 111., a corporation of Illinois Application November 9, 1934, Serial No. 752,362

31 Claims.

This invention is related to car refrigeration, and more particularly has to do with the conditioning of refrigerator cars by pre-cooling, the present application being in part a continuation of application for Letters Patent of the United States filed by me May 14, 1934, Serial No. 725,514.

Refrigerator cars are usually provided with ice tanks in the ends thereof which are charged periodically with ice and sufiicient salt to produce a brine of low temperature in the tanks.

In cars of this type the air is chilled by contact with the charged tanks and circulates under convection current influences throughout the car interior.

In certain other types of refrigerator cars the lading space inside the car is cooled by circuplaced in transit. Utilizing the refrigeration means of the car itself, whether ice tanks, or brine circulation, or ice machine, a period of approximately one or more days is ordinarily required to lower the temperature of the car sufficiently to receive its load, which period represents a very great loss to the railroads and shippers by reasonof the fact that during such pre-cooling period the car is out of service.

It is also necessary, in the case of long hauls, to re-ice at intervals, and stations are provided at various points for that purpose. Ordinarily, the ice is not all melted when a car reaches an icing station, and when that is the case a mere replenishing of the ice at the station will suffice. But in those cases where, by reason of delay in transit or for some other cause, the tanks have become depleted, and the temperature within the car has risen above that required for efficient preservation of the lading, it is highly desirable to re-chill the car morequickly than can be accomplished by merely charging with ice and salt.

The present invention contemplates, not the substitution of other refrigerating means for the ice usually employed, nor any change in the construction and arrangement of the ice tanks in the cars, but rather the provision of a method of rapidly reducing the temperature of an ordinary car through the utilization of quickly-acting low temperature cooling agents in association with the ice tanks, whereby the car may be I initially pro-chilled with great rapidity, or maybe re-chilled if desired with equal rapidity at any of the icing stations along the route. This results not only in a great saving of time at the starting point and at the icing stations,- but also in a substantial saving in the amount of ice required, and in a decided increase in the length of time during which the car'will remain cold, as well as in a marked improvement in the conditions under which the lading will be maintained from the time it is placed in the car until it reaches its destination, all of which factors are, of considerable importance in the distribution of perishable commodities.

The objects of the invention are attained by using an ordinary refrigerator car equipped with the usual ice tanks for chilling which act to establish convection current circulation of air within the car, and providing means for the application of a low temperature cooling agent 1 so arranged that it can be brought conveniently into operation to chill quickly the walls of the ice tanks whereby to cause the air which circulates in contact with the outer sides of the tank walls to become chilled and circulate through the car interior.

In this way a refrigerator car of ordinary type can be quickly pre-chilled even while being loaded, prior to icing in the usual manner, and later along the road can be re-chilled by a similar application of a cooling agent, either with or without subsequent re-icing.

By pre-chilling in the manner hereinafter set forth, it is to be observed that the cooling agent is maintained out of contact with the car interior. Thus the interior is not adversely affected with circulating air laden with the cooling agent, and the pre-chilling can be done, if 40 desired, after the car has been loaded without any danger of damage to the lading. For the same reason the interior hardware of the car is much less likely to be adversely affected.

, Preferred embodiments of the invention are .presented herein for the purpose of exempliflcation, but it will be understood, of course, that the invention is capable of beingpracticed or utilized in other modified forms which come equally within the scope of the appended claims, wherefore the drawing and description are to be taken in an illustrative and not in an unnecessarily limiting sense.

In the accompanying drawing,

Fig. 1 shows in vertical longitudinal section empty ice tanks in the end of the car;

Fig. 2 is a transverse section through one end of the car, showing the 'ice tanks and the location of the applying means for the cooling agent and drain-ofi equipment employed in the initial prechilling or en route re-chilling operation; and

,Flgs. 3 and 4 are fragmentary sectional views of the ice tanks illustrating alternative means which may be utilized for application of the cooling agent to these tanks.

The cooling agent which is preferred for accomplishing the pre-chilling of the car is a low temperature brine, but 'it is obvious that any other a known medium for this purpose may be employed and substituted for the brine, so that the utility of the present invention is not limited to the particular cooling agent that may be selected. It is also preferred to apply the cooling agent by spraying the same into the interior of the ice tanks. Alternative means, however, for such application also may be employed, as will appear hereinafter, so that the invention is not limited to spraying in order to apply the cooling agent to the useful purpose for which it is intended by the present invention.

Referring to the drawing, the wall of the refrigerator car is shown at H, the floor at I2, and the roof at l3. Within each end of the car is arranged the'usual battery of ice tanks l4, which tanks are provided adjacent their lower ends with separate suitably valved outlets Ha controlled by conveniently located operating handles Mb. The tanks H in ordinary practice are supplied with ice from above through openings which are provided with hatches IS. The tanks are separated in the usual manner from the lading space of the car by a protective bulkhead I6. This bulkhead preferably is spaced from the ceiling and floor of the car, so as to function as an airguiding baflle which is effective to permit the -.-warm air in the car to move into contact with the tanks at the top of the car, and thereafter retain the air in intimate association with theexterior surfaces of the tanks to effect its cooling, as a result of which the cooled air moves downwardly by gravity and returns to the lading space by moving outwardly away from the tanks below the bulkhead. A tray I1 is located below the tanks l4 for preventing any discharge from the tanks from running back into the car interior. This drip tray is provided with an outlet pipe l8 which extends down through the floor of the car. The

construction, thus far described is that which is found in many present day refrigerator cars of approved design. The present invention may be practiced advantageously with a car of this type, but it is not limited in its application and may be used with other cars of somewhat different types.

According .to the invention, additional cover members 2| are provided for the openings in the top of the car above the ice tanks, as clearly shown in Fig. 2, and through these'cover members a number of branch pipes 22 extend. downwardly from header pipes 23 on the outside of the car. These pipes, together with the cover members, are all readily removable, and the .pipes 23 are connected at one side of the track to a suitable source of the cooling agent, preferably, as hereinbefore stated, low temperature brine, maintained under pressure. The pipes 22 terminate within the upper portions of the ice tanks in n zzles 24 of a type which will spray the cooling agent laterally into downwardly-movable sheet contact with the inner surfaces of the walls of the tanks. A funnel I9 is provided alongside the track beneath the previously mentioned waste outlet l8 in the floor of the car, and whenthe car is in position to receive the cooling agent through the pipes 22, the outlet l8 may be placed in communication with the funnel 19 by an extension pipe l8a whereby to salvage the cooling agent that has passed through the tanks. The funnel I9 is connected by a pipe 20 to the source of the cooling agent, whereby to return the warm cooling agent thereto for re-use after it has served its purpose in cooling the tanks l4.

During the application of the cooling agent to the tanks l4 the valves Ma are kept open to permit the cooling agent which is flowing down the inner surfaces of the tanks to discharge into the drip pan l1 and return to the source of supply.

In Figs. 3 and 4 are disclosed alternative means for applying the cooling agent to the interior of the ice tanks l4. The arrangement disclosed in Fig. .3 contemplates the use of a perforated pipe 25 arranged at the upper end of each of the ice tanks and conforming to the configuration thereof. To the pipe 25 is connected a supply pipe 26 which leads from the source of the cooling agent. When, therefore, the cooling agent is introduced to the pipe 25 the same will discharge through .the perforations thereof against the inner walls of the ice tanks andgravitate in sheets or curtains along the innerwalls, thereby reducing the temperature of the same.

In Fig. 4 the alternative arrangement is illustrated as including a trough 21, which extends about the upper end of each of the tanks I4, and is so related to-the inner walls of the tank that the cooling agent introduced to the trough will overflow from the latter and gravitate to the lower end of the tank, descending along the inner faces of the walls, and thereby lowering 'the temperature thereof. The trough 21 may be supplied with the cooling agent by pipe 28, which leads from the source of the agent, and supplies a series of discharge nozzles 29 with the cooling agent for discharge into the trough 21.

The operation, in general, is as follows: With the car positioned adjacent to the source of cooling agent, the hatches l5 are opened, the usual insulated hatch plugs removed, and the cover members 2| substituted, together with the branch pipes 22, which pipes are so positioned as to cause the nozzles 24 thereon to project downwardly into proper relation to the upper, open' ends of the ice tanks. The .cooling agent, which is conducted to the car under pressure through the pipes 23, is then sprayed laterally by the nozzles so as to cover completely the inner walls of the tanks, running down the same in films or sheets to the bottom and passing out through the open valves Ila for return to the source of supply of the cooling agent. The films or sheets of cooling agent, running down the inner surfaces of the walls of the tanks, effect av'ery rapid chilling of the metal walls, the heat removal causing the outer surfaces of the walls to assume substantially the same low temperature. Convective air currents are set up within the car interior, passing through the opening at the top of the bulkhead l6 and flowing downwardly between the bulkhead and the outer walls of the tanks. Upon reaching the floor of the car about the tanks the cooled air will move back-into the car interior along the floor and Walls. As the air passes over the walls and floor it extracts heat which increases the temperature of the circulating air and causes it to rise and establish convective currents within the car. These currents act to carry the heated air along the roof of the car towards the opening between the bulkhead and the tanks and thereby complete the cycle. s

The pre-chilling may begin before the loading and may continue concurrently therewith, and also may be continued after the car is filled and the door is closed, until suflicient heat is extracted from the air of the car interior, from the car walls, and from the lading to produce the desired low temperature condition within the car. After this pre-chilling operation has been completed, the covers 2! with their spray pipes 22 are removed, and the tanks are charged with ice in the customary manner and to the usual extent, the car then being ready to proceed on its way, iced in the usual manner.

The length of haul is materially increased over former practice by the more thorough pre-chilling of the car with the low temperature cooling agent within the tanks J4, by which proceeding the residual sensible heat within the car walls and the cargo is materially reduced, The prechilling operation .will extract the heat from the car and cargo to such an extent before the rar is started in transit that the ice placed in the tanks-after the preliminary conditioning operation will be required only to take care of the heat which is absorbed subsequently through the in-- it may be said that, as a general proposition, when a refrigerator car is conditioned in accordance for conditioning is required.

As illustrated and described; the invention isapplied to refrigerator cars. It -is obvious, however, that the same is adaptable to automobile refrigerator trucks without departing from the essential characteristics of the inventionin its application to refrigerator cars, and it is to be understood that such extended application is within the purview of the invention; r

Whether the cooling agent beapplied to the walls of the tanks II by spraying, as illustrated in Figs. 1 and 2, by the perforated pipe 25"of Fig. 3, or by the trough 21 of Fig. 4, it will be obvious that the tank walls are subjected to intimate contact by the cooling agent, and that such contact is maintained for the desired time. This provides continuously-during such contact, a wetted cool- "ing surface on the tanks over substantially the entire surface area thereof.-

1 claim: 1. The method of conditioning refrigerator cars, which consists in subjecting the inner walls of the cooling tanks thereof to contact by a low temperature refrigerating. agent to reduce the temperature of said walls, permitting the refrigair within the car, then removing the refrigerat-1 ing agent from the tanks, and continuing the cycle until the desired temperature conditions within .the car have been attained.

3. The method of conditioning refrigerator cars, which consists in subjecting the inner walls of the cooling tanks thereof to contact by a low temperature refrigerating agent to reduce the temperature of said walls, permitting the refrigerating agent to be diffused progressively over I the walls and thereby reduce the temperature of the tanks to cool the air within the car, and then removing the refrigerating agent from the tanks.

4. The method of conditioning refrigerator cars, which consists in subjecting the inner walls of the cooling tanks thereof to contact by a low temperature refrigerating agent to reduce the temperature of said walls, permitting the refrigerating agent to be diffused progressively over the walls and thereby reduce the temperature of the tanks to cool the air within the car, then removing the refrigerating agent from the tanks, and continuing the cycle until the desired temperature conditions within the car have been attained.

5. The method of conditioning refrigerator cars, which consists in introducing to the interior of the cooling tanks thereof a low temperature refrigerating agent capable of difiusion over the inner surfaces of the walls of the tanks, permitting the refrigerating agent to flow in a diffused state over the walls and -thereby reduce the temperature of thetanks to cool the air within the car, and then removing the refrigerating agent from the tanks.

6. The method of conditioning refrigerator cars, which consists in introducing to the interior of the cooling'tanks thereof a low temperature refrigerating agent capable of diffusion over the inner surfaces of the walls of the tanks, permitting the refrigerating agent to fiow in a diffused state over the walls and thereby reduce the temperature of the tanks to cool the air within the car, then removing the refrigerating agent from the tanks, and continuing the cycle until the desired temperature conditions within the car have been attained.

7. The method of conditioning refrigerator cars, which consists in subjecting the inner walls of the cooling .tanks thereof to contact by a low temperature refrigerating agent to reduce the temperature of said walls, permitting the refrigerating agent to gravitate in a film or sheet over the inner surfaces of the walls and thereby reduce the temperature of the tanks to cool the air within the car, and then removing the refrigerating agent from the tanks.

8. The method of conditioning refrigerator cars, which consists in subjecting the inner walls of the cooling tanks thereof to contact by a low temperature refrigerating agent to reduce the temperature of said walls, permitting the refrigerating agent to gravitate in a film or sheet over the inner surfaces of the walls and thereby reduce the temperature of the tanks to'co'ol the air within the car, then removing the refrigerating agent from the tanks, and continuing the cycle until the desired temperature conditions within the car have been attained.

9. The" method of conditioning refrigerator cars, which consists in subjecting the inner walls of the cooling tanks thereof to the action of a low temperature refrigerating agent applied thereto in a diffused state, whereby to reduce the temperature of said walls, permitting the refrigerating agent to move relatively to said walls to ,establish progressive cooling thereof and to induce convective circulation of the air within the car without contact of the air with the refrigerating agent, and then removing the refrigerating agent from the tanks.

10. The method of conditioning refrigerator cars, which consists in spraying the inner surfaces of the walls of the tanks with a low temperature liquid while thetanks are still empty, allowing the liquid to drain oil. from the tanks during the spraying operation, and continuing the spraying operation until the circulation of air in the car induced by contact of the same with the cold outer surfaces of the walls of the tanks has lowered the temperature of the car to the required point.

11. The method of refrigerating cars containing tanks, which consists in spraying the inside walls of the tanks with a low temperature fluid, and circulating air within the car over and in contact with the'outside walls of the tanks.

12. The method of pre-chilling refrigerator cars containing ice tanks, which consists in spraying the insidewalls of the empty tanks with low temperature brine, and circulating the air within the car over and in contact with the outside walls of the tanks.

13. The method of conditioning refrigerator cars for transit, which comprises subjecting the walls of cooling tanks thereof to intimate contact by a low temperature liquid to impart to said walls a desired reduced temperature, and maintaining said contact to provide continuously for a desired time a wetted cooling surface on said tanks over substantially the entire surface thereof.

14. The method of conditioning refrigerator cars for transit, which comprises subjecting the walls of cooling tanks thereof to intimate contact by a low temperature liquid to lower the temperature of said walls, and maintaining the cooling action of said liquid upon said walls by continuing said intimate contact and thereby inducing a convective circulation of the air within the car until the desired cooling thereof is attained.

1'5. The method of conditioning refrigerator cars for transit, which comprises subjecting the walls of cooling tanks thereof to intimate contact by a low temperature liquid to lower the temperature of said walls, and maintaining the cooling action of said liquid upon said walls by continuing said intimate contact and.thereby inducing a convective circulation of the air within the car without i contact of said air with said liquid until the desired cooling of the car is attained.

16. The method of refrigerating cars contain-- ing tanks, Which comprises flowing a low temperature fluid over the inside walls of the tanks and circulating air within the car over and in contact with the outside walls of the tanks.

17. A refrigerator car comprising, in combination, a tank exposed to the air in the car, means for causing a low temperature fluid to contact withthe inner surface of the wall of said tank and to flow thereover, and a pipe for conveying fluid from the outside of said car to the first mentioned means. I

18. A refrigerator car comprising,in combination, a tank exposed to the air in the car, means adjacent the upper portion of said tank for causing a low temperature fluid to contact with the inner surface of a wall of said tank and t 6 flow downwardly thereover, and a pipe for conveying fluid from the outside of said car to the first mentioned means.

19. In a refrigerator car, the combination with a tank which is exposed to the air in the car, of 10 a nozzle which is so positioned with respect to the tank as to discharge against the inner surfaces of the walls thereof, and a pipe for conveying a refrigerating fluid to the nozzle from outside of the car.

20. In a refrigerator car, the combination with a tank which is exposed to the air in the car, and. an air directing passage adjacent the tank having air inlet and outlet communication with the compartment adjacent the tank, of a nozzle which is disposed within the tank for discharg 4 ing upon the inner surfaces of the walls thereof, and a pipe for conveying a refrigerating fluid to the nozzle from outside of the car.

21. Refrigerating apparatus comprising the 26 combination with a refrigerator car, of an ice tank exposed to the air in the car, a bulkhead extending alongside the tank in spaced relation thereto and having an upper air inlet and a lower an outlet in communication with the interior 80 of the car, a nozzle arranged within the upper portion of the tank for spraying fluid upon the inner surfaces of the walls thereof, and a pipe for supplying a refrigerating fluid to the nozzle from outside of the car.

22. Refrigerating apparatus comprising the combination with a refrigerator car, of a series of tanks exposed therein, nozzles disposed within the upper portions of the tanks and arranged to spray a fluid over the inner surfaces of the walls 40 thereof, and means for supplying low temperature refrigerating fluid to the nozzles from outside of the car.

23. In a refrigerator car, the combination with a tank which is exposed to the air in the car, of a 46 conduit arranged within the tank and adapted to discharge a cooling agent against the inner walls thereof, said conduit having a partconforming to the configuration of the tank and provided with discharge means, whereby the cooling agent dis- 50 charged by the conduit is directed to all portions of the-inner walls and caused to flow in sheets or curtains over said walls for reducing the temperature thereof.

24. In a refrigerator car, the combination with a tank which is exposed to the air in the car and provided with an open end, of a-perforatcd pipe arranged within the open end of the tank and adapted to discharge a cooling agent against the inner walls thereof, said pipe conforming to the configuration of the tank, whereby the cooling agent discharged by the pipe is directed to all portions of the inner walls and caused to gravitate in sheets or curtains over said walls for reducing the temperature thereof.

25. In a refrigerator car, the combination with a tank which is exposed to the air in the car, of a perforated pipe arranged within the tank and extending around the inner walls thereof, 'said pipe being adapted to discharge a cooling agent against the inner walls of the tank, whereby the cooling agent discharged by the pipe is directed to all portions of the inner walls and caused to flow in sheets or curtains over said walls for reducing the temperature thereof. 7

26. In a refrigerator car, the combination with a tank which'is exposed to the air in the car and provided with an open end, of means for feeding a cooling agent to said tank, and means associated with the tank for directing the cooling agent from the feeding means to the interior of the tank, whereby the cooling agent is caused to be diffused over the inner walls of the tank for reducing the temperature of said walls.

2'7. In a refrigerator car, the combination with a tank which is exposed to the air in the car and provided with an open end, of means for feeding a cooling agent to said tank, and means surrounding the open end of the tank for directing the cooling agent from the feeding means to the interior of the tank, whereby the cooling agent is caused to be diffused over the inner walls of the tank for reducing the temperature of said walls.

28. In a refrigerator car, the combination with a tank which is exposed to the air in the car and provided with an open end, of means for feeding a cooling agent to said tank, and means arranged at the exterior of the tank at the open end thereof and adapted to direct the cooling agent from the feeding means to the interior of the tank, whereby the cooling agent is caused to be diffused over the inner walls of the tank for reducing the temperature of said walls.

29. In a refrigerator car, the combination with a tank which is exposed to the air in the car and having an upper open end, of means for feeding a cooling agent to said tank, and means surrounding the upper open end of the tank for directing the cooling agent from the feeding means to the interior of the tank, whereby the cooling agent is directed to all portions of the inner walls and caused to flow in sheets or curtains over said walls 5 for reducing the temperature thereof.

30. In a refrigerator car, the combination with a tank which is exposed to the air in the car and provided with an upper open end, of means for feeding a cooling agent to said tank, and a trough surrounding the upper open end of the tank and discharging into said open end, whereby to direct the cooling agent from the feeding means to the 'interior of the tank and to cause the cooling agent to gravitate over all portions of the inner l5 walls in sheets or curtains for reducing the temperature thereof.

31. In a refrigerator car, the combination with a tank which is exposed to the air in the car and provided with an upper open end, of a pipe for supplying a cooling agent to said tank, a plurality of divergently extending nozzles carried by said pipe for feeding the cooling agent to said tank, and a trough surrounding the upper open end of the tank for receiving the cooling agent discharged by said nozzles and directing the cooling agent to the interior of the tank, whereby the cooling agent is caused to gravitate in sheets or curtains over all portions of said inner walls for reducing the temperature thereof.

DAVID P.'M1NARD. 

